Get the cursor position in input or textarea

How to get cursor position in input/textarea?

// get current cursor position
function getCursorPos(el) {
    var start = 0, end = 0, normalizedValue, range, textInputRange, len, endRange;

    start = el.selectionStart;
    if (typeof start === 'number') {
        end = el.selectionEnd;
    } else {
        range = document.selection.createRange();

        if (range && range.parentElement() === el) {
            len = el.value.length;
            normalizedValue = el.value.replace(/\r\n/g, '\n');

            // Create a working TextRange that lives only in the input
            textInputRange = el.createTextRange();
            textInputRange.moveToBookmark(range.getBookmark());

            // Check if the start and end of the selection are at the very end
            // of the input, since moveStart/moveEnd doesn't return what we want
            // in those cases
            endRange = el.createTextRange();
            endRange.collapse(false);

            if (textInputRange.compareEndPoints('StartToEnd', endRange) > -1) {
                start = end = len;
            } else {
                start = -textInputRange.moveStart('character', - len);
                start += normalizedValue.slice(0, start).split("\n").length - 1;

                if (textInputRange.compareEndPoints('EndToEnd', endRange) > -1) {
                    end = len;
                } else {
                    end = -textInputRange.moveEnd('character', - len);
                    end += normalizedValue.slice(0, end).split('\n').length - 1;
                }
            }
        }
    }

    return {start: start, end: end};
}

for more complex example, please see code in: http://rangy.googlecode.com/svn/trunk/demos/position.html